body
  margin 0

.loader
  position absolute
  top 50%
  left 40%
  margin-left 10%
  transform translate3d(-50%,-50%,0)

.dot
  width 24px
  height 24px
  background #3ac
  border-radius 100%
  display inline-block
  animation slide 1s infinite

for n in (1..5)
  .dot:nth-child({n})
    animation-delay (.1s * n)
    background red(#3ac, (50 * n))

@keyframes slide
  0%
    transform scale(1)
  50%
    opacity .3
    transform scale(2)
  100%
    transform scale(1)